changeset 51576:de5bf3fe0233

revset: stop serializing node when using "%ln"

Turning hundred of thousand of node from node to hex and back can be slow… what
about we stop doing it?

In many case were we are using node id we should be using revision id. However
this is not a good reason to have a stupidly slow implementation of "%ln".

This caught my attention again because the phase discovery during push make an
extensive use of "%ln" or huge set. In absolute, that phase discovery probably
should use "%ld" and need to improves its algorithmic complexity, but improving
"%ln" seems simple and long overdue. This greatly speeds up `hg push` on
repository with many drafts.

Here are some relevant poulpe benchmarks:

### data-env-vars.name                             = mozilla-try-2023-03-22-zstd-sparse-revlog
  # benchmark.name                                 = hg.command.push
  # bin-env-vars.hg.flavor                         = default
  # bin-env-vars.hg.py-re2-module                  = default
  # benchmark.variants.explicit-rev                = all-out-heads
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.protocol                    = ssh
  # benchmark.variants.reuse-external-delta-parent = default

 ## benchmark.variants.revs                        = any-1-extra-rev
before: 44.235070
after:  20.416329 (-53.85%, -23.82)
 ## benchmark.variants.revs                        = any-100-extra-rev
before: 49.234697
after:  26.519829 (-46.14%, -22.71)



### benchmark.name                = hg.command.bundle
  # bin-env-vars.hg.flavor        = default
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.revs       = all
  # benchmark.variants.type       = none-streamv2
 ## data-env-vars.name            = heptapod-public-2024-03-25-zstd-sparse-revlog
before:  10.138396
after:    7.750458  (-23.55%, -2.39)
 ## data-env-vars.name            = mercurial-public-2024-03-22-zstd-sparse-revlog
before:   1.263859
after:    0.700229  (-44.60%, -0.56)
 ## data-env-vars.name            = mozilla-try-2023-03-22-zstd-sparse-revlog
before: 399.484481
after:  346.5089 (-13.26%, -52.98)
 ## data-env-vars.name            = pypy-2024-03-22-zstd-sparse-revlog
before:   4.540080
after:    3.401700  (-25.07%, -1.14)
 ## data-env-vars.name            = tryton-public-2024-03-22-zstd-sparse-revlog
before:   2.975765
after:    1.870798  (-37.13%, -1.10)

--- a/mercurial/revset.py	Tue Apr 09 14:41:48 2024 +0200
+++ b/mercurial/revset.py	Fri Apr 05 11:05:54 2024 +0200
@@ -149,6 +149,22 @@
         return x & subset
 
 
+def raw_node_set(repo, subset, x, order):
+    """argument is a list of nodeid, resolve and use them"""
+    nodes = _ordered_node_set(repo, x)
+    if order == followorder:
+        return subset & nodes
+    else:
+        return nodes & subset
+
+
+def _ordered_node_set(repo, nodes):
+    if not nodes:
+        return baseset()
+    to_rev = repo.changelog.index.rev
+    return baseset([to_rev(r) for r in nodes])
+
+
 def rangeset(repo, subset, x, y, order):
     m = getset(repo, fullreposet(repo), x)
     n = getset(repo, fullreposet(repo), y)
@@ -2772,6 +2788,7 @@
     b"parent": parentspec,
     b"parentpost": parentpost,
     b"smartset": rawsmartset,
+    b"nodeset": raw_node_set,
 }
 
 relations = {

--- a/mercurial/revsetlang.py	Tue Apr 09 14:41:48 2024 +0200
+++ b/mercurial/revsetlang.py	Fri Apr 05 11:05:54 2024 +0200
@@ -392,7 +392,7 @@
     elif op == b'negate':
         s = getstring(x[1], _(b"can't negate that"))
         return _analyze((b'string', b'-' + s))
-    elif op in (b'string', b'symbol', b'smartset'):
+    elif op in (b'string', b'symbol', b'smartset', b'nodeset'):
         return x
     elif op == b'rangeall':
         return (op, None)
@@ -441,8 +441,9 @@
         return 0, x
 
     op = x[0]
-    if op in (b'string', b'symbol', b'smartset'):
-        return 0.5, x  # single revisions are small
+    if op in (b'string', b'symbol', b'smartset', b'nodeset'):
+        # single revisions are small, and set of already computed revision are assumed to be cheap.
+        return 0.5, x
     elif op == b'and':
         wa, ta = _optimize(x[1])
         wb, tb = _optimize(x[2])
@@ -784,6 +785,8 @@
             if isinstance(arg, set):
                 arg = sorted(arg)
             ret.append(_formatintlist(list(arg)))
+        elif t == b'nodeset':
+            ret.append(_formatlistexp(list(arg), b"n"))
         else:
             raise error.ProgrammingError(b"unknown revspec item type: %r" % t)
     return b''.join(ret)
@@ -801,6 +804,10 @@
             newtree = (b'smartset', smartset.baseset(arg))
             inputs.append(newtree)
             ret.append(b"$")
+        elif t == b'nodeset':
+            newtree = (b'nodeset', arg)
+            inputs.append(newtree)
+            ret.append(b"$")
         else:
             raise error.ProgrammingError(b"unknown revspec item type: %r" % t)
     expr = b''.join(ret)
@@ -863,6 +870,12 @@
                 ret.append((b'baseset', arg))
                 pos += 1
                 continue
+            elif islist and d == b'n' and arg:
+                # we cannot turn the node into revision yet, but not
+                # serializing them will same a lot of time for large set.
+                ret.append((b'nodeset', arg))
+                pos += 1
+                continue
             try:
                 ret.append((None, f(list(arg), d)))
             except (TypeError, ValueError):